By convention, rise/fall time measurements are made with the trigger levels set to 10% (start) and 90% (stop) of the maximum pulse amplitude. For ECL circuits, the reference levels are instead nominally 20 % (start) and 80 % (stop). In this case one can use Relative Trigger Levels mode and set trigger levels to 20% and 80% respectively.

Figure 39. Rise Time and Fall Time measurement

These are not a back-to-back measurement, meaning that there is a dead-time of 50 ns between the samples.

Rise Time and Fall Time functions can measure up to 2 signals in parallel with up to 16 million samples per session total.

Rise-Fall Time function can measure only 1 signal but provides both rise and fall time at once. Up to 8 million samples total can be measured in one measurement session.

Figure 40. Rise Time vs Rise-Fall Time